. >> wednesday, president obama and mitt romney meet in their first presidential debate. the news hour's jim lehrer moderates from the university of denver. watch and engage with c-span with the live debate, and followed by two ways to watch the debate at 9:00 o'clock, on c-span, both candidates on screen, the entire debate and on c-span2, the multi-camera version of the debate and following, your reactions, calls, e-mails, tweets. fog our live coverage on c-span, c-span radio, and online at c-span.org. >> >> the book is "third party matters" and joining from us tamper kwrarbgs florida is the author donald green. appreciate you being with us on c-span. guest: thank you. host: when have third parties made the biggest difference in american politics? guest: well, i think they've been -- there have been over 103rd parties since 1832. my book focuses on 11 parties i feel have made a difference. the two most significant parties in a sense are the two of the smaller ones, which is ralph nader in 2000, who changed the outcome to the election in florida and therefore nationally p